Patent Blue Derivatized Dendronized Iron Oxide Nanoparticles for Multimodal Imaging

Dendronized nanoparticles were designed for the bimodal (optical and magnetic) detection of lymph nodes with a hand-held probe during surgery. Patent Blue VF dye and iron oxide nanoparticles with 20 nm diameter, displaying high magnetization and located at the superparamagnetic/blocked monodomain boundary, were associated through a dendritic PEGylated coating to obtain stable water suspensions. Conjugation procedures (the sulfonamide link formed between the PEGylated dendron and the dye, together with the phosphonate anchoring on the iron oxide surface) were shown to be strong enough to survive in vivo conditions when the prepared nanohybrids were tested in an inflammatory node model. Moreover, magnetization of 20 nm nanoparticles increased when dendrons were grafted onto the surface, showing that they are good candidates for magnetic particle imaging, which requires high magnetization values. Preliminary lymphatic node uptake experiments performed in an inflammatory animal model showed higher uptake of the 10 nm nanoparticles relative to that of 20 nm nanoparticles. The highest probe concentration was reached 2 d after injection.